Creep and fatigue lifetime analysis of directionally solidified superalloy and its brazed joints based on continuum damage mechanics at elevated temperature

Shi, Duoqi; Dong, Chaofang; Sun, Yi-Zhi; Wang, Jingke; Liu, Jinlong

doi:10.1016/j.matdes.2012.09.052

Cited by 44 publications

(11 citation statements)

References 16 publications

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“…Based on the Palmgren-Miner rule, the fatigue damage of blade is calculated as Eq. (6): (6) where N fi is the number of cycles to failure at the ith cyclic stress and n i is the number of cycles at the ith cyclic stress. The fracture time at a constant stress is calculated based on Larson-Miller equation (7):…”

Section: Fatigue Testing Load Spectrummentioning

confidence: 99%

Failure assessment of the first stage high‐pressure turbine blades in an aero‐engine turbine

Shi

Wang

Yang

et al. 2017

Fatigue Fract Eng Mat Struct

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In this paper, microscopic analysis and fatigue experiment were conducted to detect the damage degree of turbine blades after a 600 h service and determine the reliable service time. First, several service blades were cut into slices on different cross sections and microscopically examined. It is found that the γ′ phase particles are slightly coarsened and the γ′ phase parameters change with temperature and stress distribution. Then, fatigue test was conducted on service blades simulating the real working condition. The test result shows that the blades after a 600 h service would serve for 3596 h more until failure during actual flight. The ultimate fracture is mainly caused by the interaction of fatigue, creep and oxidation. Besides, the γ′ phase parameters change obviously compared with service blade without fatigue test. It indicates that the γ′ phase parameters could be used to evaluate the microdamage of service blades, which has great significance for service reliability of the turbine machinery.

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Section: Fatigue Testing Load Spectrummentioning

confidence: 99%

Failure assessment of the first stage high‐pressure turbine blades in an aero‐engine turbine

Shi

Wang

Yang

et al. 2017

Fatigue Fract Eng Mat Struct

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“…Shi et al [15] investigated the properties of DZ125 joints, and the results showed that the post-brazing heat treatment is a useful approach to increase significantly both the creep and fatigue lifetime of the brazed joints. Therefore, it can be deduced that some properties of FGH96/DD6 joints after heat treatment will increase remarkably.…”

Section: Effect Of Dht On Mechanical Properties Of Fgh96/dd6 Jointsmentioning

confidence: 99%

Dissimilar joining of P/M superalloy and single crystal superalloy using Ni–Cr–B brazing alloy

et al. 2015

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An advanced technology for joining powder metallurgy (P/M) superalloy and single crystal (SC) superalloy is highly needed for fabricating a high-strength turbine bladed disk and the joints must meet the requirements of harsh working conditions. In the present paper, P/M superalloy FGH96 and SC superalloy DD6 were joined together using a Ni-Cr-B brazing alloy. The microstructure of the joint brazed at 1120°C for 10 min showed that massive Ni 3 B phase was formed in the central part of the brazing seam. In the FGH96 matrix near the brazing seam, a small bright phase which contained some element B, Cr, Mo, and W distributed along with grain boundary. The joints were subjected to a diffusion heat treatment at 1000°C for 1, 4, and 16 h, respectively. The results showed that the diffusion depth of B is increased from 80 μm at 1000°C/1 h to 140 μm at 1000°C/16 h. In addition, the bright phase was refined obviously, implying the homogenization of the joint microstructure. Compared with the joints treated for 1 and 4 h, the strength of the joints treated for 16 h was increased remarkably from 604∼630 to 913 MPa.

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“…Different forms of damage constitutive equations have been proposed to predict service life of engineering com ponent operated at high temperature [14][15][16]. In the early years the equations proposed mainly focused on some single factor, such as load.…”

Section: Constitutive Model and Materials Parametersmentioning

confidence: 99%

Effect of Temperature on Damage Evolution of Cr25Ni35Nb Alloy Subjected to Combined Mechanical and Environmental Degradation

Shen

Huan-sheng

Gong

et al. 2015

High Temperature Materials and Processes

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Due to combined mechanical and environ mental degradation, i.e. coupled creep and carburization, Cr25Ni35Nb alloy often fails prior to the expected design life. In the present paper, based on the continuum damage mechanics, the constitutive model of coupled multi damage factors for computing the damage evolution of Cr25Ni35Nb alloy was proposed. The damage prediction was carried out by using finite element method based on ABAQUS code. And then damage evolution processes at different operating temperatures (950 °C and 1050 °C) were simulated and the effect of service temperature on the damage evolution was discussed. The results showed that the rate of damage increased obviously with operat ing temperature increasing. The location with maximum damage is along the inner surface of tube, which implies that fracture begins along the inner surface of tube under the action of coupled creep and carburization damage and this is coincident with the actual observation of the failure of furnace tube.

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Creep and fatigue lifetime analysis of directionally solidified superalloy and its brazed joints based on continuum damage mechanics at elevated temperature

Cited by 44 publications

References 16 publications

Failure assessment of the first stage high‐pressure turbine blades in an aero‐engine turbine

Failure assessment of the first stage high‐pressure turbine blades in an aero‐engine turbine

Dissimilar joining of P/M superalloy and single crystal superalloy using Ni–Cr–B brazing alloy

Effect of Temperature on Damage Evolution of Cr25Ni35Nb Alloy Subjected to Combined Mechanical and Environmental Degradation

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